FIG. 30 shows an example of a sealing member fitting apparatus 100 according to the prior art (see JP 2004-42234A). The sealing member fitting apparatus 100 automatically fits a hollow sealing member on one end portion of an electrical wire and comprises a rubber plug transfer mechanism 110 and an electrical wire insertion device 120. The rubber plug transfer mechanism 110 comprises a rubber plug holding member 111, a middle pin 113, and a fitting pin 112. The rubber plug holding member 111 is passed through a rubber plug and holds the rubber plug S in position as it is fed through a tube by compressed air or the like. The middle pin 113 transfers the rubber plug S to the fitting pin 112 by fitting the fitting pin 112 over the rubber plug S in a transfer position A. The rubber plug S that is fitted over the fitting pin 112 in the transfer position A is then transported to a fitting position B by a rotary pin holder 114 that rotates the fitting pin 112 180 degrees.
The electrical wire insertion device 120 comprises a rubber plug holder 121, an electrical wire guide 122, an anti-buckling guide 123, and an electrical wire clamp 124. The rubber plug holder 121 holds the rubber plug S that is transported to the fitting position B by the fitting pin 112 and fits the rubber plug S on an electrical wire W. The rubber plug holder 121 comprises a chuck cylinder 126 and a pair of gripping arms 127 (left and right gripping arms) that are opened and closed by the chuck cylinder 126. The chuck cylinder 126 is fastened to a movable base stand 132 that can move in a horizontal direction (left-right direction in FIG. 30) along a guide rail 131 fastened to a base stand 130. Semicircular grooves 128 that have the same shape as the rubber plug S are formed at tip end portions of the gripping arms 127. When the gripping arms 127 are closed, the semicircular grooves 128 form a circular opening that accommodates and holds the rubber plug S that is fitted over the fitting pin 112.
The electrical wire guide 122 is installed facing the gripping arms 127 of the rubber plug holder 121 and is used to position and hold a tip end T of the electrical wire W by causing this tip end member T to coincide with an axial core of the fitting pin 112. The electrical wire guide 122 comprises a chuck cylinder 134 and a pair of gripping arms 135 (left and right gripping arms) to be opened and closed by the chuck cylinder 134. Semicircular grooves 136 having a radius which is such that the total of the respective radii is slightly larger than an external diameter of the electrical wire W are formed at tip end portions of the individual gripping arms 135. When the gripping arms 135 are closed, the semicircular grooves 136 of the gripping arms 135 form a circular opening that holds the tip end T of the electrical wire W by allowing the tip end T to be fitted with play inside the aperture. The chuck cylinder 134 is fastened to the movable base stand 132.
The anti-buckling guide 123 is used to hold the electrical wire W between the electrical wire guide 122 and the electrical wire clamp 124 that is installed away from the electrical wire guide 122 and to prevent the electrical wire W from drooping and buckling. The anti-buckling guide 123 comprises a chuck cylinder 138 and a pair of gripping arms 139 (left and right gripping arms) to be opened and closed by the chuck cylinder 138. Semicircular grooves 140 having a radius which is such that the total of the respective radii is slightly larger than the external diameter of the electrical wire W are formed at tip end portions of the individual gripping arms 139. When the gripping arms 139 are closed, the semicircular grooves 140 of the gripping arms 139 form a circular opening that holds the electrical wire W by allowing the electrical wire W to be fitted with play inside the opening. The chuck cylinder 138 is fastened to the base stand 130 and therefore does not move in the horizontal direction.
The electrical wire clamp 124 comprises a pair of gripping arms 143 (left and right gripping arms) pivoted about a supporting shaft 142 that is fastened to the base stand 130. Semicircular grooves (not shown) having a radius which is such that the total of the respective radii is the same as the external diameter of the electrical wire W are formed at tip end portions of the individual gripping arms 143 in a manner facing each other. When the gripping arms 143 are closed, the semicircular grooves (not shown) of the gripping arms 143 form a circular opening that grips the electrical wire W. The gripping arms 143 are opened and closed by an air cylinder (not shown) that is fastened to the base stand 130.
When the rubber plug S is to be fitted on the electrical wire W by the rubber plug fitting apparatus 100, the rubber plug S that is fitted over the fitting pin 112 and transported to the fitting position B is first held by the rubber plug holder 121. The electrical wire W is held by the electrical wire guide 122, the anti-buckling guide 123, and the electrical wire clamp 124, and the electrical wire W and the fitting pin 112 are disposed in a straight line. Here, an electrical wire insertion opening (not shown) that allows the insertion of the tip end T of the electrical wire W is formed at a tip end portion of the fitting pin 112, and the electrical wire W and fitting pin 112 are disposed such that the electrical wire insertion opening (not shown) and the tip end T of the electrical wire W face each other.
The movable base stand 132 is then moved toward the base stand 130, so that the rubber plug holder 121 is caused to move, together with the fitting pin 112, in a direction approaching the electrical wire W thereby inserting the tip end T of the electrical wire W into the electrical wire insertion opening (not shown) in the fitting pin 112 to a specified length. Only the fitting pin 112 is caused to move in the direction away from the electrical wire W without moving the rubber plug holder 121. When this is done, because the rubber plug S is held by the rubber plug holder 121, the fitting pin 112 is removed from the rubber plug S, so that the rubber plug S is fitted on the electrical wire W at a specified location.
Thus, with the rubber plug fitting apparatus 100 shown in FIG. 30, by using a construction in which the rubber plug S is fitted over the fitting pin 112 having an electrical wire insertion opening (not shown) formed therein, and the tip end T of the electrical wire W is then inserted into the electrical wire insertion opening (not shown) in the fitting pin 112, the insertion resistance during the insertion of the electrical wire W into the rubber plug S can be reduced, so that buckling of the electrical wire W can be prevented.
However, in the rubber plug fitting apparatus 100 shown in FIG. 30, when the electrical wire W is to be held by the electrical wire guide 122 and anti-buckling guide 123, it is necessary to manually perform the setting of the electrical wire W on the semicircular grooves 136 of the gripping arms 135 of the electrical wire guide 122 and the setting of the electrical wire W on the semicircular grooves 140 of the gripping arms 139 of the anti-buckling guide 123. Accordingly, the rubber plug fitting apparatus 100 has a problem in that it is difficult to increase the operation efficiency.